Direct Imaging

Transit Method

Radial Velocity Method

Microlensing

The region around a star where liquid water can exist on the surface of a planet

The region around a star where temperatures are suitable for life

The region around a star where planets are most likely to form

The region around a star where exoplanets are most likely to be found

An equation that estimates the number of extraterrestrial civilizations in the Milky Way galaxy

An equation that estimates the number of exoplanets in the Milky Way galaxy

An equation that estimates the number of stars in the Milky Way galaxy

An equation that estimates the age of the Milky Way galaxy

A model that suggests that planets form by the gradual accumulation of small particles

A model that suggests that planets form by the direct collapse of a cloud of gas and dust

A model that suggests that planets form by the collision of two or more large bodies

A model that suggests that planets form by the capture of interstellar objects

A hypothesis that suggests that Jupiter migrated inward during the early history of the Solar System

A hypothesis that suggests that Jupiter migrated outward during the early history of the Solar System

A hypothesis that suggests that Saturn migrated inward during the early history of the Solar System

A hypothesis that suggests that Saturn migrated outward during the early history of the Solar System

The problem of explaining why some exoplanets are very close to their host stars

The problem of explaining why some exoplanets are very far from their host stars

The problem of explaining why some exoplanets are very large

The problem of explaining why some exoplanets are very small

A region in the size distribution of exoplanets where there are few planets with radii between 1.5 and 2 Earth radii

A region in the size distribution of exoplanets where there are few planets with radii between 2 and 3 Earth radii

A region in the size distribution of exoplanets where there are few planets with radii between 3 and 4 Earth radii

A region in the size distribution of exoplanets where there are few planets with radii between 4 and 5 Earth radii

A relationship between the mass and radius of an exoplanet that is similar to the relationship between the mass and radius of a star

A relationship between the mass and radius of an exoplanet that is different from the relationship between the mass and radius of a star

A relationship between the mass and radius of an exoplanet that is not well understood

A relationship between the mass and radius of an exoplanet that is not known

Tidal forces can cause exoplanets to become tidally locked to their host stars

Tidal forces can cause exoplanets to migrate inward or outward in their orbits

Tidal forces can cause exoplanets to heat up

All of the above

The search for Earth-like exoplanets in the habitable zones of their host stars

The study of the atmospheres of exoplanets

The search for life on exoplanets

All of the above